This invention relates to computer keyboards, and more particularly to external keyboards for use with general purpose portable microcomputers.
Portable "personal" computers have developed from the early cumbersome suitcase design to smaller laptops designs to the now commercially-predominant notebook, sub-notebook and palm top computers. The evolution has been toward smaller, lighter computers with increasing transportability and usability. The state of the art continues to improve by (i) increasing battery life, (ii) decreasing circuitry and system weight, (iii) adapting compartments for add-in cards, and (iv) decreasing housing size.
The typical portable computer includes a display screen housing hinged to a keyboard housing. The display screen housing folds down against the keyboard where the two housings latch together. A disk drive often is mounted in the keyboard housing. Additional features include input/output ports and one or more compartments for receiving PCMCIA cards, (peripheral devices conforming to the Personal Computer Memory Card International Association (PCMCIA) standards for personal computer-based peripherals).
A trade-off widely accepted in portable computer design is to limit the size of the embedded keyboard relative to the conventional "full-sized" keyboards used with desktop general purpose micro-computers. The decreased size and weight increases transportability, but compromises usability. Specifically, the portable computer keyboard often has keys closer together and/or smaller than the full-size keyboard. In addition, the portable computer keyboard keys typically have a shorter key height and travel a shorter path when pressed. Often certain specialty keys are positioned in different relative locations compared to the full-size keyboard. Users may get used to the embedded keyboard or just remain frustrated committing repeated typing errors.
To partially circumvent this shortcoming, many portable computers include a port allowing connection of an external full-size keyboard. The user who does so gets the benefit of the full-size keyboard features, but suffers other inconveniences. Presently, the user plugs the external keyboard into the external keyboard port, then places the external keyboard in front of the portable computer. As shown in FIG. 1, the display screen 12, attached to the portable computer 10, is separated from the user by both the smaller embedded keyboard 14 and the external full-size keyboard 16.
The set-up with both keyboards in plain view presents visual and operational inconveniences for the user. With regard to the visual inconveniences, the user sees two distinct keyboards at all times. This is aesthetically annoying and even confusing. The user's field of view is cluttered by two sets of letter, number, function and navigation keys. The extra visual stimuli is often distracting. Minimal visual distraction is preferred so one may focus on the work (or play) at hand. The user also is further displaced from the display screen by at least the space occupied by the embedded keyboard. Given the typically small size and often mediocre visual properties of many portable computer display screens, it is preferable to give the user the option of residing closer to the display screen.
With regard to the operational inconveniences, the external keyboard occupies a significant extra "footprint." With the trend being for increasingly mobile and increasingly flexible work habits, many users do not want to devote precious desk space to an extra keyboard. Accordingly, it is desirable to provide a keyboard solution without significantly increasing the computer and keyboard "footprint."
The external keyboard, due to its need for additional space, also discourages its use at other than a base location. Users are unlikely to transport the external keyboard with the portable computer for use at other locations, in part because of the extra space requirements.
Improvements in the portable computer keyboard area have been focused on removable keyboards, additional plug-in numeric keypads, and more recently, fold out "butterfly" keyboards. The fold-out keyboards are directed at enlarging the key layout area to improve usability. However, such keyboards still are limited to the shorter key heights and travel paths of the typical portable computer keyboard. In addition such keyboards are generally flat and do not allow the inclines or adjustable inclines of conventional full-size external keyboards. This invention is directed toward improving the usability of full-size external keyboards with portable computers.